Helianthemum canadense or Crocanthemum canadense (known as longbranch frostweed, Canada frostweed, frostweed, rock frost, frostplant, or frostwort) is a species of rock-rose (Cistaceae), native to eastern North America.

It is a flowering perennial 8–24 inches (200–610 mm) in height that blooms from May to June for a single day.

The flower is yellow in color, with five petals and is between 3/4 and 1+1⁄4 inches across.

The leaves are covered in hairs and alternate in pattern.

The stems are also covered in hairs and are brown or green in color.